US11639051B2 - Pressurized reduction of CNT resistivity - Google Patents
Pressurized reduction of CNT resistivity Download PDFInfo
- Publication number
- US11639051B2 US11639051B2 US17/087,972 US202017087972A US11639051B2 US 11639051 B2 US11639051 B2 US 11639051B2 US 202017087972 A US202017087972 A US 202017087972A US 11639051 B2 US11639051 B2 US 11639051B2
- Authority
- US
- United States
- Prior art keywords
- carbon nanotube
- nonwoven sheet
- sheet
- nanotube nonwoven
- resistivity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active, expires
Links
- 230000009467 reduction Effects 0.000 title description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 123
- 239000002041 carbon nanotube Substances 0.000 claims abstract description 114
- 229910021393 carbon nanotube Inorganic materials 0.000 claims abstract description 112
- 238000000034 method Methods 0.000 claims abstract description 29
- 238000003825 pressing Methods 0.000 claims abstract description 20
- 239000000463 material Substances 0.000 claims description 23
- 238000010438 heat treatment Methods 0.000 claims description 14
- 239000000853 adhesive Substances 0.000 claims description 13
- 230000001070 adhesive effect Effects 0.000 claims description 13
- 229910052782 aluminium Inorganic materials 0.000 claims description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 10
- 239000011888 foil Substances 0.000 claims description 8
- 239000003365 glass fiber Substances 0.000 claims description 8
- 238000005411 Van der Waals force Methods 0.000 claims description 5
- 239000011347 resin Substances 0.000 claims description 5
- 229920005989 resin Polymers 0.000 claims description 5
- 229920000642 polymer Polymers 0.000 claims description 4
- -1 polytetrafluoroethylene Polymers 0.000 claims description 3
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 3
- 230000003247 decreasing effect Effects 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 16
- 239000000523 sample Substances 0.000 description 9
- 239000010408 film Substances 0.000 description 7
- 239000002313 adhesive film Substances 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 4
- 229910021387 carbon allotrope Inorganic materials 0.000 description 3
- 238000007596 consolidation process Methods 0.000 description 3
- 230000003993 interaction Effects 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000001311 chemical methods and process Methods 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000004593 Epoxy Substances 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- FFBHFFJDDLITSX-UHFFFAOYSA-N benzyl N-[2-hydroxy-4-(3-oxomorpholin-4-yl)phenyl]carbamate Chemical compound OC1=C(NC(=O)OCC2=CC=CC=C2)C=CC(=C1)N1CCOCC1=O FFBHFFJDDLITSX-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 229910021389 graphene Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000003278 mimic effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 239000002074 nanoribbon Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
- B32B37/10—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the pressing technique, e.g. using action of vacuum or fluid pressure
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B64D15/00—De-icing or preventing icing on exterior surfaces of aircraft
- B64D15/12—De-icing or preventing icing on exterior surfaces of aircraft by electric heating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/14—Layered products comprising a layer of metal next to a fibrous or filamentary layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/20—Layered products comprising a layer of metal comprising aluminium or copper
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
- B32B37/12—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by using adhesives
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
- B32B5/022—Non-woven fabric
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/14—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by a layer differing constitutionally or physically in different parts, e.g. denser near its faces
- B32B5/147—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by a layer differing constitutionally or physically in different parts, e.g. denser near its faces by treatment of the layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
- B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
- B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
- D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
- D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
- D04H1/4209—Inorganic fibres
- D04H1/4242—Carbon fibres
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06C—FINISHING, DRESSING, TENTERING OR STRETCHING TEXTILE FABRICS
- D06C15/00—Calendering, pressing, ironing, glossing or glazing textile fabrics
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06C—FINISHING, DRESSING, TENTERING OR STRETCHING TEXTILE FABRICS
- D06C7/00—Heating or cooling textile fabrics
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2250/00—Layers arrangement
- B32B2250/03—3 layers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2255/00—Coating on the layer surface
- B32B2255/06—Coating on the layer surface on metal layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2255/00—Coating on the layer surface
- B32B2255/26—Polymeric coating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
- B32B2260/02—Composition of the impregnated, bonded or embedded layer
- B32B2260/021—Fibrous or filamentary layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
- B32B2260/04—Impregnation, embedding, or binder material
- B32B2260/046—Synthetic resin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/10—Inorganic fibres
- B32B2262/101—Glass fibres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
- B32B2262/10—Inorganic fibres
- B32B2262/106—Carbon fibres, e.g. graphite fibres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2305/00—Condition, form or state of the layers or laminate
- B32B2305/10—Fibres of continuous length
- B32B2305/20—Fibres of continuous length in the form of a non-woven mat
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
- B32B2307/202—Conductive
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/724—Permeability to gases, adsorption
- B32B2307/7242—Non-permeable
- B32B2307/7244—Oxygen barrier
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/732—Dimensional properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2605/00—Vehicles
- B32B2605/18—Aircraft
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/32—Rotors
- B64C27/46—Blades
- B64C27/473—Constructional features
- B64C2027/4733—Rotor blades substantially made from particular materials
- B64C2027/4736—Rotor blades substantially made from particular materials from composite materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06C—FINISHING, DRESSING, TENTERING OR STRETCHING TEXTILE FABRICS
- D06C15/00—Calendering, pressing, ironing, glossing or glazing textile fabrics
- D06C15/02—Calendering, pressing, ironing, glossing or glazing textile fabrics between co-operating press or calender rolls
-
- D—TEXTILES; PAPER
- D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- D10B2101/00—Inorganic fibres
- D10B2101/10—Inorganic fibres based on non-oxides other than metals
- D10B2101/12—Carbon; Pitch
- D10B2101/122—Nanocarbons
Definitions
- Carbon nanotubes are carbon allotropes having a generally cylindrical nanostructure. They have unusual properties that make them valuable for many different technologies. For instance, some CNTs can have high thermal and electrical conductivity, making them suitable for replacing metal heating elements. Due to their much lighter mass, substituting CNTs for metal heating components can reduce the overall weight of a heating component significantly. This makes the use of CNTs of particular interest for applications where weight is critical, such as in aerospace and aviation technologies.
- Carbon nanotubes are commercially available in several different forms.
- One such form is as a pure carbon nanotube nonwoven sheet material (CNT-NSM).
- CNT-NSM carbon nanotubes are arranged together to form a sheet.
- No adhesives or polymers are used to attach CNTs to one another in a CNT-NSM. Instead, CNT particles are attached to one another via Van der Waals forces.
- the electrical conductivity of these commercially available, off-the-shelf CNT-NSMs is generally in the range of 350-400 Siemens/cm or lower. This level of electrical conductivity is not suitable for many aerospace heating applications (e.g., anti-icing and de-icing).
- commercially available CNT-NSMs cannot currently be used as a substitute for metal heating elements.
- a method for reducing the resistivity of a carbon nanotube nonwoven sheet includes providing a carbon nanotube nonwoven sheet comprising a plurality of carbon nanotubes and applying pressure to the carbon nanotube nonwoven sheet to reduce air voids between carbon nanotubes within the carbon nanotube nonwoven sheet.
- FIG. 1 is a schematic view of a magnified portion of a carbon nanotube nonwoven sheet material (CNT-NSM).
- CNT-NSM carbon nanotube nonwoven sheet material
- FIG. 2 is a schematic view of an embodiment of a carbon nanotube nonwoven sheet material (CNT-NSM) consistent with the Example.
- CNT-NSM carbon nanotube nonwoven sheet material
- This disclosure provides methods for reducing the resistivity of a carbon nanotube (CNT) nonwoven sheet material (CNT-NSM).
- the resistivity of a CNT-NSM is reduced by removing air voids between CNTs within the CNT-NSM. Air voids are removed from the CNT-NSM by the application of pressure to the CNT-NSM.
- the disclosed methods allow for the improvement of CNT heating elements without the addition of mass or the addition of functional groups using chemical processes.
- FIG. 1 schematically illustrates one example of a portion of a carbon nanotube nonwoven sheet.
- CNT nonwoven sheet 10 includes a plurality of carbon nanotubes (CNTs) 12 that are attached together to form sheet 10 .
- CNT nonwoven sheet 10 is generally manufactured as a flat sheet or tape that is very thin, as thin as or thinner than the thickness of an ordinary sheet of paper (about 0.07 to 0.18 millimeters).
- the length and width of sheet 10 can vary depending on manufacturer or customer selection.
- CNT nonwoven sheets are available from Nanocomp Technologies, Inc./Huntsman Advanced Materials of Merrimack, N.H. under the Miralon® brand.
- FIG. 1 schematically illustrates a magnified view of sheet 10 to illustrate individual CNTs 12 .
- CNT nonwoven sheet 10 includes only carbon nanotubes 12 and sheet 10 is free of the adhesives, resins and polymers that are often used as a matrix that incorporate CNT particles.
- CNTs 12 are held together by Van der Waals forces or interactions. Van der Waals forces are non-covalent and non-ionic attractive forces between CNTs caused by fluctuating polarizations of the CNTs.
- Individual carbon nanotubes 12 can align themselves by pi-stacking, one type of Van der Waal interaction. Pi-stacking refers to attractive, non-covalent interactions between aromatic rings that occur due to the presence of pi bonds.
- CNT-NSMs As each carbon ring within a CNT possesses pi bonds, pi-stacking occurs between nearby CNTs 12 .
- pure CNT-NSMs such as sheet 10
- they are sometimes referred to as “dry” sheets.
- air voids 14 are present between some adjacent CNTs 12 .
- Air voids 14 present in sheet 10 increase the resistivity (and reduce the conductivity, which is inversely proportional to the resistivity) of sheet 10 .
- Air voids 14 are present in commercially available CNT-NSMs to such an extent that they increase the resistivity of sheet 10 and render them unsuitable for many anti-icing and de-icing applications on aircraft.
- the lowest claimed resistivity of one commercially available, off-the-shelf CNT-NSM is about 0.4 ohms per square ( ⁇ /sq) 1 .
- the resistivity of a heating element should be 0.1 ⁇ /sq or lower to provide sufficient anti-icing and/or de-icing.
- pressure is applied to commercially available CNT-NSMs to remove air voids 14 present in sheet 10 to decrease the resistivity of sheet 10 .
- the application of pressure makes sheet 10 suitable for additional heating applications for which untreated CNT-NSMs are not. 1
- the unit of measure for resistivity of a thin film material measured using a four point probe technique is ohms-per-square. The measured result is equal to the resistance between two electrodes on opposite sides of a theoretical square. The size of the square is unimportant.
- Pressure can be applied to CNT nonwoven sheet 10 using different methods.
- pressure is applied to sheet 10 using a machine press.
- the machine press can include two opposing plates that are pressed together with sheet 10 positioned between the two plates.
- the size and/or number of air voids 14 present within sheet 10 are reduced. Reducing the size and number of air voids 14 in sheet 10 allows CNTs 12 within sheet 10 to be positioned closer together, thereby reducing the resistivity of sheet 10 .
- the amount of pressure applied to sheet 10 by the plates can vary depending on the amount of air voids 14 present in sheet 10 and the amount of air voids 14 desired in sheet 10 after pressing.
- the applied pressure can be up to about 689 kPa (100 psig) or higher.
- the applied pressure can be about 571 kPa (75 psig).
- the applied pressure can be as high as possible as long as air voids 14 are being reduced in size and/or number and significant damage to sheet 10 is avoided.
- a layer of foil or other material can be positioned on one or both sides of sheet 10 prior to pressing.
- sheet 10 can be sandwiched between two layers of aluminum foil.
- the side of the aluminum foil that contacts sheet 10 can be coated with polytetrafluoroethylene or another low surface energy material to prevent sheet 10 from sticking to the aluminum foil during or after pressing.
- one or both of the plates can include a surface pattern that has one or more protrusions or recesses to provide greater or lesser pressure application at various locations of sheet 10 . The surface pattern(s) allow for localized areas of varying resistivity on sheet 10 . Sheet 10 then can be used in applications where varying resistivity of a heating element is desirable.
- Heat energy can also be applied to sheet 10 before, during or after the application of pressure to sheet 10 .
- the application of heat may further aid in the reduction of the size and/or number of air voids 14 present within sheet 10 .
- One or both of the opposing plates of the machine press can be heated such that when the plates are pressed together, both pressure and heat energy is delivered to sheet 10 .
- This pressure and heat energy are applied to sheet 10 essentially simultaneously.
- the plates can be heated to a temperature of about 100° C. (212° F.).
- sheet 10 can be heated to a temperature as high as possible as long as air voids 14 are being reduced in size and/or number and significant damage to sheet 10 is avoided.
- sheet 10 can be heated to a temperature within the above range.
- pressure is applied to sheet 10 using a set of nip rollers.
- Nip rollers are cylindrical rollers through which sheet 10 is fed.
- the outer diameter surfaces of two nip rollers are separated by a distance that is less than the thickness of sheet 10 .
- the distances between the outer diameter surfaces of the nip rollers can vary along the interfacing length of the nip rollers.
- pressure is applied by the nip rollers to sheet 10 .
- the pressures disclosed above with respect to the machine press can also be applied by a set of nip rollers.
- a set of nip rollers includes two or more rollers through which sheet 10 passes.
- the set of nip rollers can be heated in a fashion similar to the plates of a machine press to add heat energy at the time pressure is applied to sheet 10 .
- an autoclave is used to apply pressure to sheet 10 .
- Sheet 10 is positioned within the pressure chamber of an autoclave and sheet 10 is subjected to elevated pressure and temperature within the autoclave.
- the pressures and temperatures disclosed above with respect to the machine press can also be applied by an autoclave.
- the methods of pressure application disclosed above describe the application of pressure to a pure CNT-NSM, such as CNT nonwoven sheet 10 .
- the same methods can also be applied to a CNT nonwoven sheet that includes a backing material.
- the CNT nonwoven sheet can be layered on top of or beneath a backing material layer or sheet.
- the combined CNT nonwoven sheet and backing material can then be pressed using a machine press or set of nip rollers or positioned in an autoclave for pressure application.
- the backing material can be attached to a CNT nonwoven sheet by an adhesive or resin and then pressed or autoclaved.
- Suitable backing materials include glass fibers and pre-pregs (e.g., composite fibers in an epoxy matrix).
- Each sample 20 had a base layer 22 of aluminum (to represent the skin of an aircraft part) onto which were applied a first layer 24 and a second layer 26 of film adhesive.
- a CNT nonwoven sheet 28 (Miralon® CNT nonwoven sheet produced by Nancomp Technologies, Inc./Huntsman Advanced Materials of Merrimack, N.H.) was placed on top of the second layer 26 of film adhesive.
- the third layer 30 of film adhesive was place on top of the CNT nonwoven sheet 28 .
- Glass fiber backing layer 32 was place on top of the third layer 30 of film adhesive.
- the samples 20 were intended to mimic the structure of aircraft anti-icing and de-icing devices that include CNT nonwoven sheets 28 .
- Table 1 provides additional information about the materials used to prepare the samples:
- the sheet resistivity was measured to provide an initial sheet resistivity metric.
- Each sample was then placed into an autoclave (make, model if you have it) and subjected to the temperature and pressure schedule shown in Table 2 to remove voids from the CNT nonwoven sheet. Following consolidation in the autoclave, the sheet resistivity was measured again to provide a final sheet resistivity metric. Both the initial sheet resistivity and final sheet resistivity were determined using a four point probe resistivity technique that is well known in the art.
- Example 3 As shown in table 3, applying a combination of heat and pressure to each of the samples reduced sheet resistivity by 45% to 72%.
- Example is based on an embodiment of a CNT nonwoven sheet in combination with an aluminum sheet, adhesive layers, and a glass fiber backing layer, it is expected that the equivalent sheet resistivity reduction will be obtained with any other embodiment described in this disclosure due to consolidation of air voids and alignment of carbon nanotubes in the CNT nonwoven sheet. Decreasing sheet resistivity to the extent demonstrated in this example, makes CNT nonwoven sheets suitable for use in aircraft anti-icing and de-icing applications
- the methods disclosed herein provide means for reducing the resistivity of CNT-NSMs without increasing their mass or the chemical processes needed to add resistivity-reducing functional groups to the carbon backbone of the CNT materials.
- the disclosure allows commercially available CNT-NSMs to be useful for aerospace and aircraft anti-icing and de-icing applications.
- a method for reducing the resistivity of a carbon nanotube nonwoven sheet can include providing a carbon nanotube nonwoven sheet comprising a plurality of carbon nanotubes and applying pressure to the carbon nanotube nonwoven sheet to reduce air voids between carbon nanotubes within the carbon nanotube nonwoven sheet.
- the method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
- the method can further include heating the carbon nanotube nonwoven sheet.
- the step of applying pressure to the carbon nanotube nonwoven sheet can be performed using a machine press.
- the method can further include layering a foil on a side of the carbon nanotube nonwoven sheet prior to applying pressure to the carbon nanotube nonwoven sheet.
- the foil can include aluminum and polytetrafluoroethylene.
- the step of applying pressure to the carbon nanotube nonwoven sheet can be performed using a set of nip rollers.
- the step of applying pressure to the carbon nanotube nonwoven sheet can be performed using an autoclave.
- the carbon nanotube nonwoven sheet can include a plurality of carbon nanotubes held together by Van der Waals forces, and applying pressure to the carbon nanotube nonwoven sheet can reduce spacing between at least some adjacent carbon nanotubes.
- the carbon nanotube nonwoven sheet can contain no adhesives or resins.
- the carbon nanotube nonwoven sheet can be attached to a backing material.
- the backing material can include glass fibers.
- the backing material can include a pre-preg layer.
- the carbon nanotube nonwoven sheet can consist essentially of carbon nanotubes.
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Aviation & Aerospace Engineering (AREA)
- Nonwoven Fabrics (AREA)
Abstract
Description
TABLE 1 | |||
Layer | Sample 1 | Sample 2 | Sample 3 |
22 | Aluminum sheet, | Aluminum sheet, | Aluminum sheet, |
1.016 mm | 1.016 mm | 1.016 mm | |
(0.040 inch) | (0.040 inch) | (0.040 inch) | |
thick | thick | thick | |
24 | Film adhesive | Film adhesive | Film adhesive |
0.127 mm | 0.127 mm | 0.127 mm | |
(0.005 inch) thick | (0.005 inch) thick | (0.005 inch) thick | |
26 | Film adhesive | Film adhesive | Film adhesive |
0.127 mm | 0.127 mm | 0.127 mm | |
(0.005 inch) thick | (0.005 inch) thick | (0.005 inch) thick | |
28 | Miralon ® CNT | Miralon ® CNT | Miralon ® CNT |
nonwoven | nonwoven | nonwoven | |
sheet, | sheet, | sheet, | |
areal density = 10 | areal density = 15 | areal density = 20 | |
g/m−2-15 g/m−2 | g/m−2-20 g/m−2 | g/m−2 - 30 g/m−2 | |
30 | Film adhesive | Film adhesive | Film adhesive |
0.127 mm | 0.127 mm (0.005 | 0.127 mm (0.005 | |
(0.005 inch) thick | inch) thick | inch) thick | |
32 | Glass fiber | Glass fiber | Glass fiber |
backing layer. | backing layer. | backing layer. | |
TABLE 2 | ||||
Action | Cumulative | Pressure, | ||
Time | Time | Temperature | gauge | |
Action | minutes | minutes | ° C. (° F.) | kPa (psig) |
Start | 0 | 0 | 27 (80) | 0 |
|
30 | 30 | 107 (225) | 517 (75) |
Hold | 60 | 90 | 107 (225) | 517 (75) |
|
30 | 120 | 177 (350) | 517 (75) |
Hold | 120 | 240 | 177 (350) | 517 (75) |
Ramp | 90 | 330 | 27 (80 | 0 |
End | ||||
TABLE 3 | |||
Change in | |||
Initial Sheet | Final Sheet | Resistivity Due | |
Resistivity | Resistivity | to Consolidation | |
Sample | (ohms per square) | (ohms per square) | Process |
1 | 1.15 | 0.624 | −45.7% |
2 | 1.45 | 0.544 | −62.5% |
3 | 0.65 | 0.180 | −72.4% |
Claims (11)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US17/087,972 US11639051B2 (en) | 2016-12-08 | 2020-11-03 | Pressurized reduction of CNT resistivity |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US15/373,370 US20180162114A1 (en) | 2016-12-08 | 2016-12-08 | Pressurized reduction of cnt resistivity |
US17/087,972 US11639051B2 (en) | 2016-12-08 | 2020-11-03 | Pressurized reduction of CNT resistivity |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/373,370 Continuation-In-Part US20180162114A1 (en) | 2016-12-08 | 2016-12-08 | Pressurized reduction of cnt resistivity |
Publications (2)
Publication Number | Publication Date |
---|---|
US20210316543A1 US20210316543A1 (en) | 2021-10-14 |
US11639051B2 true US11639051B2 (en) | 2023-05-02 |
Family
ID=78007260
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US17/087,972 Active 2037-02-17 US11639051B2 (en) | 2016-12-08 | 2020-11-03 | Pressurized reduction of CNT resistivity |
Country Status (1)
Country | Link |
---|---|
US (1) | US11639051B2 (en) |
Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030198812A1 (en) | 2001-07-25 | 2003-10-23 | Thomas Rueckes | Nanotube films and articles |
US20090140098A1 (en) | 2007-11-29 | 2009-06-04 | Hauke Lengsfeld | Component with carbon nanotubes |
US20100176118A1 (en) | 2009-01-14 | 2010-07-15 | David Lee | Electric heating film and method of producing the same |
US20100259867A1 (en) * | 2007-09-28 | 2010-10-14 | Kenji Machida | Electrode for electric double layer capacitor and method for producing the same |
US20100279569A1 (en) * | 2007-01-03 | 2010-11-04 | Lockheed Martin Corporation | Cnt-infused glass fiber materials and process therefor |
EP2289803A2 (en) | 2009-08-28 | 2011-03-02 | Goodrich Corporation | Improved lightning strike protection |
US8080199B2 (en) * | 2002-12-17 | 2011-12-20 | William Marsh Rice University | Interaction of microwaves with carbon nanotubes to facilitate modification |
US20120118868A1 (en) * | 2009-02-06 | 2012-05-17 | Lg Hausys, Ltd. | Carbon nanotube-metal particle complex composition and heated steering wheel using the same |
US20130157001A1 (en) | 2011-12-19 | 2013-06-20 | E I Du Pont De Nemours And Company | Structural core |
US20130264116A1 (en) | 2012-04-09 | 2013-10-10 | Nanocomp Technologies, Inc. | Nanotube Material Having Conductive Deposits to Increase Conductivity |
US20140034633A1 (en) * | 2010-11-17 | 2014-02-06 | Battelle Memorial Institute | Carbon nanotube thin film laminate resistive heater |
WO2016126827A1 (en) | 2015-02-03 | 2016-08-11 | General Nano Llc | Electrically-conductive heating element |
-
2020
- 2020-11-03 US US17/087,972 patent/US11639051B2/en active Active
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030198812A1 (en) | 2001-07-25 | 2003-10-23 | Thomas Rueckes | Nanotube films and articles |
US8080199B2 (en) * | 2002-12-17 | 2011-12-20 | William Marsh Rice University | Interaction of microwaves with carbon nanotubes to facilitate modification |
US20100279569A1 (en) * | 2007-01-03 | 2010-11-04 | Lockheed Martin Corporation | Cnt-infused glass fiber materials and process therefor |
US20100259867A1 (en) * | 2007-09-28 | 2010-10-14 | Kenji Machida | Electrode for electric double layer capacitor and method for producing the same |
US20090140098A1 (en) | 2007-11-29 | 2009-06-04 | Hauke Lengsfeld | Component with carbon nanotubes |
US20100176118A1 (en) | 2009-01-14 | 2010-07-15 | David Lee | Electric heating film and method of producing the same |
US20120118868A1 (en) * | 2009-02-06 | 2012-05-17 | Lg Hausys, Ltd. | Carbon nanotube-metal particle complex composition and heated steering wheel using the same |
EP2289803A2 (en) | 2009-08-28 | 2011-03-02 | Goodrich Corporation | Improved lightning strike protection |
US20140034633A1 (en) * | 2010-11-17 | 2014-02-06 | Battelle Memorial Institute | Carbon nanotube thin film laminate resistive heater |
US20130157001A1 (en) | 2011-12-19 | 2013-06-20 | E I Du Pont De Nemours And Company | Structural core |
US20130264116A1 (en) | 2012-04-09 | 2013-10-10 | Nanocomp Technologies, Inc. | Nanotube Material Having Conductive Deposits to Increase Conductivity |
WO2016126827A1 (en) | 2015-02-03 | 2016-08-11 | General Nano Llc | Electrically-conductive heating element |
Non-Patent Citations (5)
Title |
---|
First Brazilian Office Action for BR Application No. BR102017024020, dated Apr. 13, 2021, pp. 6. |
Marinho et al. "Electrical conductivity of compacts of graphene, multi-wall carbon nanotubes, carbon black, and graphite powder." Power Technology 221 (2012): 351-358., retrieved on May 7, 2019 https://www.sciencedirect.com/science/article/pii/S0032591012000277 (Year: 2012). |
Marinho etc. "Electrical conductivity of compacts of graphene, multi-wall carbon nanotubes, carbon black, and graphite powder." Powder Technology 221 (2012): 351-358., retrieved on May 7, 2019 https://www.sciencedirect.com/science/article/pii/S0032591012000277 (Year: 2012). * |
Noh etc. "Improved Electrical Conductivity of Carbon Nanotube Mat Composite Prepared By In-Situ Polymerization.", 2012, retrieved on May 7, 2019 from http://confsys.encs.concordia.ca/ICCM19/AllPapers/FinalVersion/KIM80249.pdf (Year: 2012). * |
Second Brazilian Office Action for BR Application No. BR102017024020-7, dated Aug. 1, 2022, pp. 7. |
Also Published As
Publication number | Publication date |
---|---|
US20210316543A1 (en) | 2021-10-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2445714B1 (en) | Process for manufacturing composite materials | |
WO2017135234A1 (en) | Carbon nanotube twisted yarn production method and carbon nanotube twisted yarn | |
WO2011102107A1 (en) | Method for producing graphite film, method for rewinding same, and method for producing graphite composite film and graphite-free processed product | |
KR101619573B1 (en) | Manufacture method of MEA for fuel cell | |
US9296869B2 (en) | Composite materials | |
US11345066B2 (en) | Composite structures, materials with a removable backing for composite structures and related devices and methods | |
US9260633B2 (en) | Electrically conductive adhesives comprising bucky paper and an adhesive resin | |
US20180213606A1 (en) | Carbon allotrope heaters with multiple interdigitated electrodes | |
US11370893B2 (en) | Composite material, prepreg, carbon-fiber-reinforced molded body, and method for manufacturing composite material | |
US9902618B2 (en) | Carbon nanotube sheet and production method for carbon nanotube sheet | |
JP6366206B2 (en) | Multilayer device comprising a stiffener combined with a support layer by electrostatic coupling | |
JP5531389B2 (en) | Method for producing porous carbon sheet | |
US10717051B2 (en) | Carbon nanotube membrane systems and methods of synthesis | |
US9051060B2 (en) | Electromagnetic hazard protector for composite materials | |
US11639051B2 (en) | Pressurized reduction of CNT resistivity | |
JP4843396B2 (en) | Cushion material for heat press and method for producing the same | |
CN105885804A (en) | Method for preparing graphene all-carbon composite thermal interface material | |
JP2014015567A (en) | Prepreg | |
Luo et al. | A laser-fabricated nanometer-thick carbon film and its strain-engineering for achieving ultrahigh piezoresistive sensitivity | |
JP5837881B2 (en) | Electromagnetic interference protectors for composite materials | |
EP3333294B1 (en) | Pressurized reduction of cnt resistivity | |
CN103379994B (en) | The improvement of composite | |
JP2016210848A (en) | Ultrahigh-molecular weight polyethylene porous film and method for producing the same | |
CN111094410B (en) | Method for producing filler-resin composite | |
KR20240019633A (en) | Pressure sensor and pressure sensor manufacturing method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: GOODRICH CORPORATION, NORTH CAROLINA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HU, JIN;BOTURA, GALDEMIR CEZAR;SLANE, CASEY;AND OTHERS;SIGNING DATES FROM 20161208 TO 20161212;REEL/FRAME:054291/0470 |
|
FEPP | Fee payment procedure |
Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NON FINAL ACTION MAILED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: FINAL REJECTION MAILED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: RESPONSE AFTER FINAL ACTION FORWARDED TO EXAMINER |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: ADVISORY ACTION MAILED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |